A telecommunication switch as used to write message traffic over a network. Usually, it comprises a chassis or housing containing circuitry on a multiplicity of printed circuit cards which plug into a motherboard in the chassis. The various communication lines are plugged into connectors on those cards, the connectors being exposed at the back and/or front of the chassis. The actual switching may be controlled by a central processor unit (CPU) contained on one or more of the cards in accordance with programs and instructions provided from an external keyboard. The chassis usually also contains a power supply for supplying power to various parts of the switch.
Many present day switch chassis and housings are disadvantaged in that they are relatively difficult to make and to assemble so that when the various printed circuit cards are installed in the chassis, they will assuredly make good reliable electrical connections to the motherboard. Also, the interiors of the prior chassis are not always organized to promote good circulation of cooling air through the chassis so that components on all of the cards, particularly the power cards are adequately cooled. Furthermore, the interior layouts of conventional chassis are usually not flexible enough to allow for using redundant power supplies or take into account that some switches may require more switching capacity than others.